medwireNews

Global medical news in review: August 19-25, 2012

medwireNews: A roundup of select stories of interest to US physicians from the Merck Medicus Medical News wire.

USPSTF waffles on hearing screening for elderly

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A US Preventive Services Task Force (USPSTF) review of screening for hearing impairment in older, asymptomatic adults concludes that there is insufficient evidence to assess whether or not the benefits outweigh the harms.

As reported in the Annals of Internal Medicine , the statement updates the 1996 USPSTF recommendations that older adults (≥50 years) should be periodically questioned about their hearing, counseled about the availability of hearing aids, and referred where appropriate.

The USPSTF does highlight that clinicians should "understand the evidence but individualize decision making to the specific patient or situation," since clinical decisions involve more considerations than evidence alone.

Men randomly assigned to receive the androgen receptor-signaling inhibitor after chemotherapy had a median overall survival of 18.4 months compared with just 13.6 months for placebo-treated patients.

The study, published in The New England Journal of Medicine, included 1199 men treated with enzalutamide 160 mg/day (n=800) or placebo (n=399) and was halted after planned interim analysis showed a hazard ratio for overall survival of 0.63. The patient groups had received a median of 8.3 and 3.0 months' treatment, respectively.

Vitamin D supplements can reduce a child's risk for contracting acute respiratory infections (ARIs) by almost 50%, show results from a Mongolian study.

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Carlos Camargo (Harvard Medical School, Boston, Massachusetts, USA) and team carried out a randomized study in 247 Mongolian children, aged an average of 10 years. Children assigned to the intervention group (n=143) were given tasteless and colorless (for double blinding purposes) vitamin D3 300 IU/day added to milk. The children in the control group (n=104) were given the same amount of unfortified milk.

At follow-up 3 months later, children in the intervention group had a mean vitamin D level of 19 versus 7 ng/mL in the control group. They had also experienced significantly fewer ARIs, at 0.80 versus 0.45, an effective halving of the number of cases (rate ratio=0.52).

Maternal smoking during early pregnancy increases the baby's risk for asthma and wheezing in early childhood, even if the mother quits later on in the pregnancy or after giving birth, a European study shows.

Researchers found that the risk for asthma was increased even in children of mothers who only smoked during the first trimester.

"This indicates that the hazardous effects of maternal smoking on the fetal respiratory system might present before the woman knows that she is pregnant," say Anna Bergstrom (Karolinska Institutet, Stockholm, Sweden) and colleagues.

Their findings should encourage public health efforts to get mothers to quit smoking before getting pregnant, they write in the American Journal of Respiratory and Critical Care Medicine.

Findings from a retrospective study, published in Circulation, show that patients with coronary heart disease (CHD) who engage in high-intensity exercise have a similarly low risk for a cardiovascular event as those engaging in moderate-intensity exercise.

The findings are important as exercise performed at higher relative intensities has been shown to elicit greater increases in aerobic capacity and cardioprotective effects than moderate continuous training (MCT). However, concerns exist surrounding vigorous exercise and the associated increased acute risk for sudden cardiac death and myocardial infarction in susceptible individuals.

In a commentary accompanying the report, Steven Keteyian (Henry Ford Hospital, Detroit, Michigan) says the findings should be considered preliminary, given that the study is underpowered to accurately determine the safety of high-intensity interval training.

Five or more years of exposure to diabetes drugs in the thiazolidinedione (TZD) category may be associated with a higher incidence of bladder cancer than comparable exposure to sulfonylureas, according to Ronac Mamtani (University of Pennsylvania, Philadelphia) and colleagues.

Using The Health Improvement Network database, the team conducted a retrospective study of 59,855 patients with Type 2 diabetes who received a prescription for either a TZD or sulfonylurea between July 2000 and August 2010.

As reported in the Journal of the National Cancer Institute, there were 197 incident bladder cancers diagnosed over 196,708 person-years of follow-up, with incident rates of 87.1 and 107.2 per 100,000 person-years with TZD and sulfonylurea use, respectively.

The team reports that there was no significant difference in risk for bladder cancer between TZD and sulfonylurea users.

However, the risk was increased with longer time since initiation of TZD therapy. Those who initiated TZD therapy 5 years or more previously were at more than three times the risk for bladder cancer than those who had started treatment less than 1 year earlier.

Nathan Wong (University of California, Los Angeles, USA) and colleagues conducted an analysis of 13,572 individuals who participated in the National Health and Nutrition Examination Survey 1999‑2008.

As they report in The American Journal of Cardiology, individuals with elevated levels of HDL cholesterol (≥60 mg/dL) but not of CRP (3 mg/L or less), had the lowest prevalence of CHD and CVD at 3.3% and 5.0%, respectively. Conversely, those without elevated HDL cholesterol but with raised hsCRP (>3 mg/L) had the greatest prevalence, at 7.7% and 10.8%, respectively.

People with sinusitis who regularly treat their condition using nasal irrigation should be aware of a potential contamination risk associated with using inadequately filtered tap water, say US researchers. They report two deaths occurring following nasal irrigation using disinfected tap water that was contaminated with the Naegleria fowleri ameba. Both individuals had been using neti pots, a sinus irrigation device, to treat their sinusitis

Infection with N. fowleri is rare, with 32 reported cases in the USA between 2002 and 2011, but is 97% fatal. This is due to destruction of brain tissue by the organism during primary amebic meningoencephalitis following its migration up the nasal passage. Occasionally patients respond to being treated with very high doses of the antifungal drug amphotericin B, but treatment is usually given too late to be effective and even if effective has severe side effects, such as nephrotoxicity.

The two cases are described by Jonathan Yoder (Centers for Disease Control and Prevention, Atlanta, Georgia) and colleagues in Clinical and Infectious Diseases.